text: # Copyright 2017 The TensorFlow Authors. All Rights Reserved.
  #
  # Licensed under the Apache License, Version 2.0 (the "License");
  # you may not use this file except in compliance with the License.
  # You may obtain a copy of the License at
  #
  #     http://www.apache.org/licenses/LICENSE-2.0
  #
  # Unless required by applicable law or agreed to in writing, software
  # distributed under the License is distributed on an "AS IS" BASIS,
  # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  # See the License for the specific language governing permissions and
  # limitations under the License.
  # ==============================================================================
  """Handling annotations on AST nodes.
  
  Adapted from Tangent.
  """
  
  from __future__ import absolute_import
  from __future__ import division
  from __future__ import print_function
  
  
  def getanno(node, key, field_name='___pyct_anno'):
    return getattr(node, field_name)[key]
  
  
  def hasanno(node, key, field_name='___pyct_anno'):
    return hasattr(node, field_name) and key in getattr(node, field_name)
  
  
  def setanno(node, key, value, field_name='___pyct_anno'):
    annotations = getattr(node, field_name, {})
    setattr(node, field_name, annotations)
    assert not hasanno(node, key, field_name), (node, key)
    annotations[key] = value
  
    # So that the annotations survive gast_to_ast() and ast_to_gast()
    if field_name not in node._fields:
      node._fields += (field_name,)
  